scholarly journals Optical and Compositional Characters and Paleothermal Implications of a Diverse Suite of Natural Bitumens From Middle Devonian Carbonate Rocks, Pine Point, Northwest Territories

1989 ◽  
Author(s):  
D Kirste ◽  
M G Fowler ◽  
F Goodarzi ◽  
R W Macqueen
Keyword(s):  
Northwest Territories ◽  
Middle Devonian ◽  
Carbonate Rocks ◽  
Pine Point

DISCOVERY CASE HISTORY OF THE PYRAMID ORE BODIES PINE POINT, NORTHWEST TERRITORIES, CANADA

Geophysics ◽  
1968 ◽  
Vol 33 (4) ◽  
pp. 645-656 ◽  
Author(s):  
H. O. Seigel ◽  
H. L. Hill ◽  
J. G. Baird
Keyword(s):  
Northwest Territories ◽  
Time Domain ◽  
Case History ◽  
Middle Devonian ◽  
Electromagnetic Induction ◽  
Ore Bodies ◽  
Lead And Zinc ◽  
History Of ◽  
Pine Point ◽  
Devonian Age

In the fall of 1965 a geophysical exploration program, in the Pine Point area, Northwest Territories, Canada, revealed indications which led to the discovery of 11.2 million tons of ore grading 11.7 percent combined lead and zinc in two separate ore bodies. The ore bodies are relatively flat‐lying although irregular in plan and section. They lie in limestones and dolomites, some reefoidal, of Middle Devonian age and are generally conformable to these sea sediments. The basic discoveries were effected by a time‐domain, induced‐polarization survey. A subsequent gravity survey proved to be of considerable value in guiding the extensive drilling program which followed and in predicting the amount of ore to be expected in each body. Despite a high marcasite content, the ore bodies did not respond appreciably to electromagnetic induction methods. This is attributed to the mode of distribution of the various sulfide minerals in the deposits.

Characterization and dispersal of indicator minerals associated with the Pine Point Mississippi Valley-type (MVT) district, Northwest Territories, Canada

2015 ◽  
Vol 52 (9) ◽  
pp. 776-794 ◽  
Author(s):  
N.M. Oviatt ◽  
S.A. Gleeson ◽  
R.C. Paulen ◽  
M.B. McClenaghan ◽  
S. Paradis
Keyword(s):  
Northwest Territories ◽  
Major Element ◽  
Bimodal Distribution ◽  
Mississippi Valley ◽  
Element Geochemistry ◽  
Element Concentrations ◽  
Pine Point ◽  
Indicator Minerals ◽  
Mississippi Valley Type ◽  
Valley Type

A glacial dispersal study was conducted around a subcropping Pb–Zn deposit (O28) in the Pine Point Mississippi Valley-type (MVT) district, Northwest Territories, Canada, with the intent of characterizing and documenting the indicator minerals and their dispersal from a known orebody. Mapping of striations adjacent to deposit O28, and throughout the Pine Point district, along with observed glacial stratigraphy, indicate that there are three phases of ice flow that have affected the Pine Point district. Sphalerite, galena, and pyrite were identified in mineralized bedrock samples at deposit O28, and sphalerite and galena were recovered from the sand fraction of till samples up to 500 m from the mineralized subcrop. The majority of sphalerite and galena grains recovered from till samples down-ice of deposit O28 were 0.25–0.5 mm in size. Size and morphology of sphalerite grains in till demonstrate relative proximity to their bedrock source, with the largest and more angular grains being closer to the ore zone (<50 m) whereas smaller and more rounded grains occur further down-ice (∼250 m). The paragenesis, textures, major-element concentrations, and S and Pb isotopic compositions of bedrock samples from deposit O28 and from newly drilled core from four other deposits were characterized. Concentrations of Zn in bedrock sphalerite grains range from 43.95 to 67.48 wt.%, concentrations of S range from 32.03 to 34.01 wt.%, and concentrations of Fe range from 0.02 to 16.94 wt.%. The Fe concentration in bedrock sphalerite decreases from east to west across the district. Concentrations of S in galena grains in bedrock range from 12.50 to 14.00 wt.% and have a bimodal distribution. Generally, the geochemistry of sphalerite grains recovered from till were statistically similar to bedrock grains recovered from deposits O28 and L65. Major-element concentrations were statistically the same between the sphalerite grains recovered from till and the honey-brown and cleiophane varieties in the bedrock samples. Galena grains recovered from till samples were similar to the cubic and fracture-fill varieties of grains recovered from bedrock in the R190 and M67 deposits. Sulphur isotopic values for sphalerite grains from bedrock range from 20.6‰ to 24.2‰, while those from till samples range from −5.3‰ to 24.4‰. Lead isotopic ratios for galena grains from bedrock and till samples had very little variation, which is a characteristic of the Pine Point district. The S and Pb isotopic studies as well as major-element geochemistry suggest that indicator minerals derived from Pine Point-type mineralization can be distinguished from those sourced from other types of carbonate-hosted mineralized systems (e.g., Cordilleran zinc–lead deposits) and that the methods here can be used as exploration tools for identifying MVT deposit provenance or potential. The results of this study present criteria and highlights additional methods for exploration of MVT deposits in glaciated terrain.

Deformation associated with gypsum karst in the Salt River Escarpment, northeastern Alberta

1984 ◽  
Vol 21 (8) ◽  
pp. 949-959 ◽  
Author(s):  
Po C. Tsui ◽  
David M. Cruden
Keyword(s):  
Groundwater Flow ◽  
Northwest Territories ◽  
Middle Devonian ◽  
Normal Faults ◽  
Gypsum Karst ◽  
Salt River ◽  
Fort Smith ◽  
Devonian Age ◽  
Northeastern Alberta ◽  
Subsurface Cavities

An escarpment formed by the carbonate Keg River and evaporitic Chinchaga formations of Middle Devonian age extends southwards from the Slave River 30 km west of Fort Smith, Northwest Territories. Newly described folds in the bedrock are due to hydration of the anhydrite to gypsum in the Chinchaga Formation underlying the escarpment. Local groundwater flow has also dissolved subsurface cavities in the Chinchaga Formation. As these openings grew, the carbonates of the Keg River Formation subsided along stepped normal faults. Depressions within the fault blocks occurred where subsidence was concentrated along joints.

An enigmatic blastozoan echinoderm fauna from central kentucky

2009 ◽  
Vol 83 (5) ◽  
pp. 739-749 ◽  
Author(s):  
Colin D. Sumrall ◽  
Carlton E. Brett ◽  
Troy A. Dexter ◽  
Alexander Bartholomew
Keyword(s):  
North America ◽  
Northwest Territories ◽  
Middle Devonian ◽  
Fossil Record ◽  
Foreland Basin ◽  
Late Ordovician ◽  
Upper Devonian ◽  
Range Extension ◽  
First Report ◽  
Appalachian Foreland

A series of small road cuts of lower Boyle Formation (Middle Devonian: Givetian) near Waco, Kentucky, has produced numerous specimens of three blastozoan clades, including both “anachronistic” diploporan and rhombiferan “cystoids” and relatively advanced Granatocrinid blastoids. This unusual assemblage occurs within a basal grainstone unit of the Boyle Limestone, apparently recording a local shoal deposit. Diploporans, the most abundant articulated echinoderms, are represented by a new protocrinitid species, Tristomiocystis globosus n. gen. and sp. Glyptocystitoid rhombiferans are represented by isolated thecal plates assignable to Callocystitidae. Three species of blastoids, all previously undescribed, include numerous thecae of the schizoblastid Hydroblastus hendyi n. gen. and sp., the rare nucleocrinid Nucleocrinus bosei n. sp., and an enigmatic troosticrinid radial. The blastoid Nucleocrinus is typical for the age; however, the callocystitid, schizoblastid, and protocrinitid are not. Hydroblastus is the oldest known schizoblastid. Middle and Upper Devonian callocystitids have been previously reported only from Iowa and Michigan USA with unpublished reports from Missouri USA and the Northwest Territories, Canada. This occurrence is thus the first report of a Middle Devonian rhombiferan from the Appalachian foreland basin. Tristomiocystis is the first known protocrinitid in North America and the only protocrinitid younger than Late Ordovician. This occurrence thus represents a range extension of nearly 50 million years for protocrinids. This extraordinary sample of echinoderms in a Middle Devonian limestone from a well-studied area of North America highlights the incompleteness of the known fossil record, at least in fragile organisms such as echinoderms.

Pine Point orebodies and their relationship to the stratigraphy, structure, dolomitization, and karstification of the Middle Devonian barrier complex

1984 ◽  
Vol 79 (5) ◽  
pp. 991-1055 ◽  
Author(s):  
D. Rhodes ◽  
E. A. Lantos ◽  
J. A. Lantos ◽  
R. J. Webb ◽  
D. C. Owens
Keyword(s):  
Middle Devonian ◽  
Pine Point
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